Field of the Invention
The present invention relates to an in-line type film forming apparatus that performs a film forming process while sequentially transporting a substrate that is a film forming target in a plurality of vacuum chambers, and a method of manufacturing a magnetic recording medium using the same.
Priority is claimed on Japanese Patent Application No. 2013-231378, filed on Nov. 7, 2013, the content of which is incorporated herein by reference.
Description of Related Art
Recently, in a field of a magnetic recording medium that is used in a hard disk drive and the like, an improvement in a recording density is significant, and particularly, recently, the recording density has increased at a speed as astounding as 1.5 times per year. However, it is difficult to make miniaturization of a grain size, a thermo-stable characteristic, and a recording characteristic compatible with each other. That is, it is difficult to realize high-density of a medium due to the problem of this so-called trilemma.
A thermally assisted magnetic recording method is expected as a method of solving the trilemma, and research and development thereof have been actively in progress. The thermally assisted magnetic recording method is a recording method of performing recording by irradiating a medium with rear-field light by a magnetic head to locally heat a medium surface and to reduce a coercive force of the medium.
For example, the magnetic recording medium has a structure in which a seed film, an underlying film, a magnetic recording film, a protective film, and a lubricant film are sequentially laminated on both surfaces or a single surface of a non-magnetic substrate, and is typically manufactured by using an in-line type film forming apparatus that performs a film forming process while sequentially transporting a substrate, which is held by a carrier, between a plurality of vacuum chambers (for example, refer to Japanese Unexamined Patent Application, First Publication No. 2002-288888).
The in-line type film forming apparatus has a structure in which a plurality of vacuum chambers that perform a film forming process are connected to each other through a gate valve. In addition, in each of the chambers, a plurality of bearings that are rotatably supported in the horizontal axis direction are arranged and provided in a transportation direction of the carrier, and thus the carrier can move on the plurality of bearings.
In the in-line type film forming apparatus, the respective vacuum chambers are isolated by the gate valve, and then the vacuum chamber is decompressed. According to this, the film forming process can be performed in a state in which the inside of each of the vacuum chambers is set to an independent pressure condition.
The magnetic recording medium can be continuously manufactured by using the in-line type film forming apparatus. A substrate is not contaminated during handling of the substrate to be processed. Furthermore, a handling process is reduced, and thus a manufacturing process becomes efficient. In addition, a yield ratio is improved, and thus productivity of the magnetic recording medium can be increased.